Last reviewed 1 Oct 2026 · 6 min read
Why agro-waste matters
Agriculture and food processing generate huge quantities of residues (straw, husk, stalk, bagasse, shells, peels, bran, press cake). Burning them in the field wastes energy and pollutes air. Good utilisation turns them into fuel, feed, fertiliser, materials and chemicals and raises the income from processing.
Residue availability is estimated from the crop production and a residue-to-product ratio:
Major agricultural residues and their uses
| Residue | Source | Uses |
|---|---|---|
| Rice straw | Paddy | Fodder (limited), mushroom substrate, compost, packing, paper, energy; field burning is a major pollution problem |
| Rice husk (about 20–22 % of paddy) | Rice milling | Fuel for boilers and parboiling, rice-husk ash (silica for cement and steel), briquettes, gasifier fuel, insulation, bedding |
| Rice bran | Milling | Rice-bran oil (an edible oil), cattle and poultry feed, wax, and defatted bran |
| Wheat straw (bhusa) | Wheat | Cattle feed, bedding, thatching, board |
| Bagasse | Sugarcane | Boiler fuel, cogeneration, paper and pulp, particle board, compost |
| Press mud | Sugar mill | Organic manure, bio-compost, wax |
| Molasses | Sugar mill | Ethanol, cattle feed, yeast |
| Cotton stalks | Cotton | Fuel, particle board, briquettes |
| Groundnut shells | Groundnut | Fuel, briquettes, filler, activated carbon |
| Coconut shells, husk (coir), fronds | Coconut | Charcoal, activated carbon, coir products |
| Maize cobs and stalks | Maize | Fodder, fuel, furfural, activated carbon |
| Oilseed cakes | Oil milling | Cattle feed, manure (e.g., neem, castor) |
| Fruit and vegetable waste | Processing | Pectin from citrus/apple pomace, animal feed, biogas, compost |
| Animal waste and poultry litter | Livestock | Biogas, manure |
Conversion routes
| Route | Products |
|---|---|
| Direct combustion | Heat and power (boilers, furnaces, cookstoves) |
| Densification (briquetting / pelletising) | Fuel briquettes from sawdust, husk, groundnut shell and stalks; easier storage and transport |
| Gasification | Producer gas for engines and heating |
| Anaerobic digestion | Biogas and digested slurry (manure) |
| Fermentation | Ethanol (2G bioethanol from straw and bagasse) |
| Composting and vermicomposting | Organic manure |
| Pyrolysis | Biochar, bio-oil |
| Particle/fibre board and packaging | Boards from bagasse, rice husk and straw |
| Animal feed | Treated straw (urea treatment), oilseed cake, bran |